Dedifferentiation of neuroendocrine carcinoma of the uterine cervix in hypoxia

Clonal Origin and Lineage Ambiguity in Mixed Neuroendocrine Carcinoma of the Uterine Cervix

Small-cell neuroendocrine carcinoma (SCNEC) of the cervix is a rare disease characterized by a high incidence of mixed tumors with other types of cancer. The mechanism underlying this mixed phenotype is not well understood. This study established a panel of organoid lines from patients with SCNEC of the cervix and ultimately focused on one line, which retained a mixed tumor phenotype, both in vitro and in vivo. Histologically, both organoids and xenograft tumors showed distinct differentiation into either SCNEC or adenocarcinoma in some regions and ambiguous differentiation in others. Tracking single cells indicated the existence of cells with bipotential differentiation toward SCNEC and adenocarcinomas. Single-cell transcriptional analysis identified three distinct clusters: SCNEC-like, adenocarcinoma-like, and a cluster lacking specific differentiation markers. The expression of neuroendocrine markers was enriched in the SCNEC-like cluster but not exclusively. Human papillomavirus 18 E6 was enriched in the SCNEC-like cluster, which showed higher proliferation and lower levels of the p53 pathway. After treatment with anticancer drugs, the expression of adenocarcinoma markers increased, whereas that of SCNEC decreased. Using a reporter system for keratin 19 expression, changes in the differentiation of each cell were shown to be associated with the shift in differentiation induced by drug treatment. These data suggest that mixed SCNEC/cervical tumors have a clonal origin and are characterized by an ambiguous and flexible differentiation state.

ASURAT: functional annotation-driven unsupervised clustering of single-cell transcriptomes

MOTIVATION

Single-cell RNA sequencing (scRNA-seq) analysis reveals heterogeneity and dynamic cell transitions. However, conventional gene-based analyses require intensive manual curation to interpret biological implications of computational results. Hence, a theory for efficiently annotating individual cells remains warranted.

RESULTS

We present ASURAT, a computational tool for simultaneously performing unsupervised clustering and functional annotation of disease, cell type, biological process and signaling pathway activity for single-cell transcriptomic data, using a correlation graph decomposition for genes in database-derived functional terms. We validated the usability and clustering performance of ASURAT using scRNA-seq datasets for human peripheral blood mononuclear cells, which required fewer manual curations than existing methods. Moreover, we applied ASURAT to scRNA-seq and spatial transcriptome datasets for human small cell lung cancer and pancreatic ductal adenocarcinoma, respectively, identifying previously overlooked subpopulations and differentially expressed genes. ASURAT is a powerful tool for dissecting cell subpopulations and improving biological interpretability of complex and noisy transcriptomic data.

AVAILABILITY AND IMPLEMENTATION

ASURAT is published on Bioconductor (https://doi.org/10.18129/B9.bioc.ASURAT). The codes for analyzing data in this article are available at Github (https://github.com/keita-iida/ASURATBI) and figshare (https://doi.org/10.6084/m9.figshare.19200254.v4).

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

The role of long non-coding RNAs in angiogenesis and anti-angiogenic therapy resistance in cancer

It is well known that long non-coding RNAs (lncRNAs) play an important role in the regulation of tumor genesis and development. They can modulate gene expression of transcriptional regulation, epigenetic regulation of chromatin modification, and post-transcriptional regulation, thus influencing the biological behavior of tumors, such as cell proliferation, apoptosis, cell cycle, invasion, and migration. Tumor angiogenesis not only provides nutrients and helps excrete metabolites, but it also opens a pathway for tumor metastasis. Anti-angiogenic therapy has become one of the effective treatment methods for tumor. But its drug resistance leads to the limitation of clinical application. Recent studies have shown that lncRNAs are closely related to tumor angiogenesis and anti-angiogenic therapy resistance, which provides a new direction for tumor research. lncRNAs are expected to be new targets for tumor therapy. For the first time to our knowledge, this paper reviews advancement of lncRNAs in tumor angiogenesis and anti-angiogenic therapy resistance and further discusses their potential clinical application.

Hypoxia Promotes Pancreatic Cancer Cell Dedifferentiation to Stem-Like Cell Phenotypes With High Tumorigenic Potential by the HIF-1α/Notch Signaling Pathway

OBJECTIVES

This study aimed to investigate the effect and mechanism of hypoxia on pancreatic cancer (PC) cell dedifferentiation and tumorigenic potential.

METHODS

Inhibition of hypoxia-inducible factor 1α (HIF-1α) and overexpression of Notch1 in PC HS766T cell lines were by lentiviral transfection. The expression of stem cell-specific markers C-X-C motif chemokine receptor 4, CD44, and Nestin was detected by immunofluorescence and Western blot assays. Cell invasion capacity was examined by Transwell assay. Tumorigenic potential was measured in an in situ tumor transplantation experiment. The expression of HIF-1α, Notch signals, and apoptosis signals was examined by Western blot assay.

RESULTS

Hypoxia promoted PC cells to dedifferentiate into stem-like cells by upregulating HIF-1α and activating Notch signals. Silencing of HIF-1α significantly repressed cell dedifferentiation and invasion, whereas overexpression of Notch1 reversed the effect of HIF-1α repression. In situ tumor transplantation experiment further confirmed that hypoxia promoted tumorigenic ability through upregulating HIF-1α. Moreover, the expression of HIF-1α and Notch1 was significantly increased in human PC tissues, and high expression of HIF-1α was correlated with poor survival rate.

CONCLUSIONS

Hypoxia promoted PC cell dedifferentiation to stem-like cell phenotypes with high tumorigenic potential by activating HIF-1α/Notch signaling pathway, indicating a novel role in regulating PC progression.

Heterogenous chemosensitivity of a panel of organoid lines derived from small cell neuroendocrine carcinoma of the uterine cervix

Small cell neuroendocrine carcinoma (SCNEC) of the uterine cervix is a rare disease with a poor prognosis. The lack of established disease models has hampered therapy development. We generated a panel of cancer tissue-originated spheroid (CTOS) lines derived from SCNEC of the uterine cervix using a method based upon cell-cell contact throughout the preparation and culturing processes. Using 11 CTOS lines, we assessed the sensitivity of various drugs used in clinical practice. Drug sensitivity assays revealed significant heterogeneous inter-CTOS chemosensitivity. Microarray analyses were then performed to identify sensitivity-related gene signatures. Specific gene sets were identified which likely contribute to the sensitivity to the tested drugs. We identified a line (Cerv54) that was exceptionally sensitive to irinotecan. Cerv54 had increased levels of CES1, which catalyzes the conversion of irinotecan to the active form, SN38, although in Cerv54 cells, SN38 was undetectable, CES1 expression and activity were markedly low compared to the liver, and a CES1 inhibitor had no effect on irinotecan sensitivity. These results suggested a novel irinotecan mode of action in Cerv54. Our CTOS lines may be useful for understanding the variation and mechanism of drug sensitivity, contributing to the understanding and development of chemotherapeutic drugs.